C语言实现任何文件的加密解密功能

//#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>#include <string.h>#include <stdlib.h>#include<time.h>#include<sys/stat.h>  #pragma warning(disable:4996) //加密void Encryption(char *p, size_t n){ for (int i = 0; i < n;++i) { *p += 7; }} //解密void Decrypt(char *p, size_t n){ for (int i = 0; i < n;++i) { *p -= 7; }} char *EnOrDe = {0}; int main(int argc, char *args[]){ clock_t c1 = clock();//系统当前时间，毫秒为单位  char *FileNameSrc = (char *)calloc(160, sizeof(char));//待操作文件  char *p2 = (char *)calloc(200, sizeof(char));//操作后文件名  //从命令行获取文件名和要处理的操作 FileNameSrc = args[1];//文件名，包含路径  char *p1 = args[1];  EnOrDe = args[2];//en表示加密，de表示解密  /*FileNameSrc = "E://iPhone6-new.txt" ; char *p1 = FileNameSrc; EnOrDe = "de";*/   /**********处理生成新的文件名***********/ //char *p2 = { 0 }; /*FileNameSrc = p1;*/ //printf("%s/n", FileNameSrc); //printf("%s/n", EnOrDe);  int index = 0; while (*p1) { if (*p1!='.') {  *p2 = *p1;  p2++;  p1++;  index++; } else if (*p1 == '.') {  *p2 = '_';  p2++;  *p2 = 'H';  p2++;  *p2 = '.';  p2++;  p1++;  index+=2; } } printf("/n"); printf("信息摘要：/n"); printf("--------------------------------------/n"); printf("原文件:%s/n", FileNameSrc); printf("操作:%s （en――加密，de――解密）/n", EnOrDe); printf("预计结果文件:%s/n", p2 - index - 1); printf("--------------------------------------/n/n"); printf("请稍后，玩命处理中....../n");  char *FileNameDst = p2 - index - 1;  FILE *pr = fopen(FileNameSrc, "rb"); FILE *pw = fopen(FileNameDst, "wb");  struct stat st = { 0 }; size_t fileSize = st.st_size;//以字节为单位  //char *buf = NULL; //if (fileSize<1024*1024)//小于1M //{ // buf = malloc(sizeof(char) * 1024 * 20);//分配20K //} //else //{  // buf = malloc(sizeof(char)*fileSize / 10); //} char *buf = calloc(1024 * 1024 * 25, sizeof(int));//分配100M  /*************定义函数指针***************/ void(*pFunc)(char *, size_t); pFunc = NULL; if (strcmp(EnOrDe, "en") == 0) { pFunc = Encryption; } else if (strcmp(EnOrDe, "de") == 0) { pFunc = Decrypt; } /*************定义函数指针***************/   while (!feof(pr)) { //memset(buf, 0, sizeof(buf));//calloc自动初始化为0 size_t res = fread(buf, sizeof(char), sizeof(buf), pr);  pFunc(buf, res);  fwrite(buf, sizeof(char), res, pw); } fclose(pr); fclose(pw); printf("/n"); printf("--------------------------------------/n"); printf("执行成功！/n所在目录:%s/n", FileNameDst); clock_t c2 = clock();//系统当前时间，毫秒为单位 printf("耗时:%u毫秒/n", c2-c1); printf("--------------------------------------/n"); return 0;}